Question

Assertion (A): Phenols are more acidic than aliphatic alcohols
Reason (R): Phenoxides are stabilized by resonance.
A) Both assertion and reason are correct, Reason is correct explanation for Assertion
B) Both Assertion and reason are corrected, Reason is not the correct explanation of Assertion.
C)Assertion is correct but Reason is incorrect.
D)Assertion is incorrect but Reason is correct.

Answer 1

We have to look at the resonating structures of phenols. Then, we have to analyze the reason behind the acidic nature of the above- mentioned compounds. Also, we have to look into the reaction when alcohol loses its proton to form alkoxide and have to look whether there is any resonance effect taking place in that reaction.

Complete step by step answer:
According to the Lowry Bronsted theory, an acid is a substance that loses its proton and then forms corresponding salts. Acidity is the measure on a scale.
In phenols the $\, - OH\,$ group is attached to the carbon atom which is $s{p^2}$ hybridized, due to which the electron density on oxygen decreases. This increases the polarity of the $- OH$ group which results in more ionization. And thus the ${H^ + }$ ion can be easily abstracted.
Also, the loss of proton leads to formation of phenoxide ion which is more stable than corresponding phenol. In phenoxide ion the negative charge is delocalized within the ring structure which makes it more stable than the aliphatic alcohols. In aliphatic alcohols there is no such delocalization stabilization.
Therefore, phenols are more acidic and the resulting phenoxide ion is stabilized because of resonance.
When we look into the reaction of aliphatic alcohols, when it loses its protons to form alkoxide, there is no resonance taking place. Since the negative charge in the phenoxide ion is not centered on the oxygen atom, like it is in an alkoxide ion. But it is delocalized which means it is expressed by a variety of carbon atoms in the benzene loop. Hence, phenols are even more acidic than alcohols.

Hence, option A is the correct answer.

Note:
The acidity of phenols increases with the presence of electron withdrawing groups like nitro groups. Also, the compounds with smaller $pKa$ values are more acidic. However, by destabilizing the phenoxide ion, the presence of the electron release group lowers the acidity of the phenol.